U.S. patent application number 09/975916 was filed with the patent office on 2002-02-07 for digital wireless telephone system.
This patent application is currently assigned to Tokyo Digital Phone Co., Ltd.. Invention is credited to Higuchi, Kazuhisa, Kamataki, Hideki.
Application Number | 20020016190 09/975916 |
Document ID | / |
Family ID | 27330623 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020016190 |
Kind Code |
A1 |
Higuchi, Kazuhisa ; et
al. |
February 7, 2002 |
Digital wireless telephone system
Abstract
A wireless telephone system comprises a mobile station having
its reception portion turned on in timed relationship with paging
channels contained in a sending signal having been issued from a
telephone exchange to the mobile station through a base station,
and has the reception portion de-energized in the remaining period
of time, so that the intermittent standby reception operation is
performed. The exchange sends a paging message in both an
intermittent superframe reception group and a paging channel group,
for which groups the mobile station is waiting. The unit receives
broadcast information, specifies the intermittent superframe
reception group on the basis of the contents of intermittent
standby information contained in the broadcast information, and
performs its intermittent standby reception operation in the
reception group having been thus specified.
Inventors: |
Higuchi, Kazuhisa;
(Adachi-ku, JP) ; Kamataki, Hideki; (Choufu-shi,
JP) |
Correspondence
Address: |
AKIN, GUMP, STRAUSS, HAUER & FELD, L.L.P.
ONE COMMERCE SQUARE
2005 MARKET STREET, SUITE 2200
PHILADELPHIA
PA
19103
US
|
Assignee: |
Tokyo Digital Phone Co.,
Ltd.
Shinjuku-ku
JP
|
Family ID: |
27330623 |
Appl. No.: |
09/975916 |
Filed: |
October 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09975916 |
Oct 12, 2001 |
|
|
|
09116503 |
Jul 16, 1998 |
|
|
|
Current U.S.
Class: |
455/574 ;
455/343.4 |
Current CPC
Class: |
H04W 8/08 20130101; H04W
48/12 20130101; Y02D 70/00 20180101; H04W 68/00 20130101; Y02D
30/70 20200801; H04W 52/0216 20130101 |
Class at
Publication: |
455/574 ;
455/343 |
International
Class: |
H04B 001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 5, 1997 |
JP |
9-222079 |
Nov 28, 1997 |
JP |
9-341879 |
Claims
We claim:
1. A digital wireless telephone system comprising a mobile station
provided with a reception portion, which portion is timed in its
turning-on-power operation to a paging channel contained in a
sending signal issued from a telephone exchange to said mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, wherein when an intermittent
standby operation is available, said telephone exchange sends out a
paging message in an intermittent superframe reception group and in
a paging channel group, for which groups said mobile station is
waiting; and wherein said mobile station receives broadcast
information, specifies an intermittent reception group on the basis
of the contents of intermittent standby information contained in
said broadcast information, and performs its intermittent standby
reception operation in said reception group having been thus
specified, and wherein said intermittent standby reception
operation reduces power consumption of said mobile station by
arbitrarily controlling the interval of intermittent standby
reception.
2. The digital wireless telephone system as set forth in claim 1,
wherein said telephone exchange comprises: an intermittent
reception extension information setting means for setting the
contents of intermittent standby information in an extension
information element contained in the broadcast information; a
subscriber's information discriminating means for discriminating
subscriber's information; an intermittent reception group analyzing
means for analyzing said intermittent reception group of said
mobile station, on the basis of a discrimination result obtained
from said subscriber's information discriminating means and of the
intermittent standby information having been set by said
intermittent reception extension information setting means; and a
message sending means for sending out said paging message in an
intermittent reception group and said paging channel group, for
which groups said mobile station is waiting.
3. The digital wireless telephone system as set forth in claim 1,
wherein defined as the contents of intermittent standby information
in said broadcast information are: an extension information element
length; and an intermittent standby information element comprising
an intermittent standby superframe interval and an intermittent
standby superframe counter.
4. A digital wireless telephone system comprising a mobile station
provided with a reception portion, which portion is timed in its
turning-on-power operation to a paging channel contained in a
sending signal issued from a telephone exchange to said mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, wherein said telephone
exchange retrieves location information and subscriber's
information from a subscriber's information memory, and sends out a
paging message in both an intermittent superframe reception group
and a paging channel group, for which groups said mobile station is
waiting; and wherein said mobile station receives broadcast
information, specifies an intermittent reception group on the basis
of an intermittent standby superframe interval having been set in
its own unit by means of an intermittent standby superframe
counter, and performs its intermittent standby reception operation
in said reception group having been thus specified; and wherein
said intermittent standby reception operation reduces power
consumption of said mobile station by arbitrarily controlling the
interval of intermittent standby reception.
5. The digital wireless telephone system as set forth in claim 4,
wherein: said telephone exchange comprises: a Cs information
setting means for setting an intermittent standby superframe
counter information element in an extension information element
contained in said broadcast information; an intermittent reception
group analyzing means for analyzing said intermittent reception
group of said mobile station, on the basis of said location
information and said subscriber's information both retrieved from a
subscriber's information memory; and a message sending means for
sending out said paging message in said intermittent superframe
reception group and said paging channel group, for which groups
said mobile station is waiting; while said mobile station
comprises: a Pi memory means for recording said intermittent
standby superframe interval.
6. A digital wireless telephone system comprising a mobile station
provided with a reception portion, which portion is timed in its
turning-on-power operation to a paging channel contained in a
sending signal issued from a telephone exchange to said mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, wherein wherein said
telephone exchange retrieves location information and subscriber's
information from a subscriber's information memory, and
continuously sends out an inter-superframe paging message in a
paging channel group, for which groups said mobile station is
waiting, the number of said inter-superframe paging messages being
the same value as that of intermittent standby superframe
intervals; and wherein said mobile station receives broadcast
information, and performs its intermittent standby reception
operation, on the basis of both said broadcast information and the
contents of intermittent standby information which contains said
intermittent standby superframe interval having been set in its own
unit; and wherein said intermittent standby operation reduces power
consumption of said mobile station by arbitrarily controlling the
interval of intermittent standby reception.
7. The digital wireless telephone system as set forth in claim 6,
wherein: said telephone exchange comprises: a PCH group analyzing
means for analyzing said paging channel group, for which group said
mobile station is waiting, on the basis of said location
information and said subscriber's information both retrieved from a
subscriber's information memory; and a message continuously sending
out means for continuously sending out an inter-superframe paging
message in a paging channel group, for which group said mobile
station is waiting, the number of said inter-superframe paging
messages being the same value as that of intermittent standby
superframe intervals; while said mobile station comprises: an
intermittent reception information memory means for recording the
contents of intermittent standby information containing said
intermittent standby superframe interval.
8. A digital wireless telephone system comprising a mobile station
provided with a reception portion, which portion is timed in its
turning-on-power operation to a paging channel contained in a
sending signal issued from a telephone exchange to said mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, wherein said telephone
exchange retrieves location information and subscriber's
information from a subscriber's information memory, and
continuously sends out an inter-superframe paging message in a
paging channel group, for which groups said mobile station is
waiting, the number of said inter-superframe paging messages being
the same value as that of intermittent standby superframe
intervals; and wherein said mobile station receives broadcast
information, and performs its intermittent standby reception
operation, on the basis of said intermittent standby superframe
interval contained in said broadcast information; and wherein said
intermittent standby reception operation reduces power consumption
of said mobile station by arbitrarily controlling the interval of
intermittent standby reception.
9. The digital wireless telephone system as set forth in claim 8,
wherein: said telephone exchange comprises: a Pi information
setting means for setting said intermittent standby superframe
interval information element in an extension information element
contained in said broadcast information; a PCH group analyzing
means for analyzing said paging channel group, for which group said
mobile station is waiting, on the basis of said location
information and said subscriber's information both retrieved from a
subscriber's information memory; and a message continuously sending
out means for continuously sending out an inter-superframe paging
message in a paging channel group, for which group said mobile
station is waiting, the number of said inter-superframe paging
messages being the same value as that of said intermittent standby
superframe intervals.
10. The digital wireless telephone system as set forth in claim 1,
wherein: in an intermittent reception state, said mobile station
measures a perch channel in a peripheral zone after completion of
reception of said paging channel in timing, the number of said
peripheral zones to be measured being the same value as that of
said intermittent standby superframe intervals.
11. The digital wireless telephone system as set forth in claim 1,
wherein: in an intermittent reception state, said mobile station
measures a perch channel in a peripheral zone each time a
superframe appears.
12. The digital wireless telephone system as set forth in claim 1,
said mobile station comprising: analyzing means for analyzing the
intermittent standby information contained in said broadcast
information; measuring means for measuring a bit error rate and a
reception level; and control means for control of said mobile
station that performs high efficiency intermittent reception in
case said control means recognizes the presence of the intermittent
standby information and that a prescribed value of said bit error
rate and of said reception level each exist.
13. The digital wireless telephone system as set forth in claim 1
said mobile station comprising: analyzing means for analyzing the
intermittent standby information contained in the broadcast
information; measuring means for measuring a bit error rate and a
reception level; and control means for control of said mobile
station that stops high efficiency intermittent reception and
performs ordinary reception in case said mobile station recognizes
the intermittent standby information does not exist, or either of
the bit error rate or the reception level have an inappropriate
value.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. patent
application Ser. No. 09/116,503, filed Jul. 16, 1998, entitled
"Digital Wireless Telephone System" which is hereby incorporated by
reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a digital wireless
telephone system, and more particularly to a digital wireless
telephone system, in which a mobile station is improved in
efficiency of the intermittent reception operation in its standby
mode reducing power consumption.
[0004] 2. Description of the Related Art
[0005] In the digital wireless telephone system, since the mobile
station uses a battery as its own power source, it is very
important for the mobile station to reduce its power consumption.
In this connection, various types of techniques have been developed
to reduce the power consumption of the mobile station. Of these
techniques, a so-called battery saving technique has been widely
used, in which technique the mobile station has its reception
portion intermittently operated in its standby mode to reduce its
power consumption. FIG. 8(a) shows a conventional intermittent
reception operation of the mobile station in its standby mode.
Transmitted at predetermined time intervals in a sending signal
used in the conventional intermittent reception operation of the
mobile station are time slots each containing paging information of
the mobile station. The reception portion of the mobile station has
its own power source turned on in timed relationship with paging
channels (i.e., P); and turned off in the remaining period of time.
For example, in the Digital Mobile-Phone System Standards (i.e.,
RCR STD-27) prepared by the Denpa Sangyo kai (i.e., ARIB), there is
stipulated the intermittent reception operation of the mobile
station for saving its battery power in the standby mode in a radio
zone. An interval used in such intermittent reception operation
stipulated in the above Standards is equal to one superframe
interval (i.e., 720 milliseconds) at maximum.
[0006] However, in the conventional intermittent reception
operation with such one superframe interval at maximum, it is not
possible to increase a continuous standby period of time, and,
therefore often not possible to increase the efficiency of the
intermittent reception operation. Further, the conventional
intermittent reception operation with such one superframe interval
at maximum is disadvantageous in that it can not set arbitrarily
the continuous standby period of time.
BRIEF SUMMARY OF THE INVENTION
[0007] Under such circumstances, the present invention was made.
Consequently, it is an object of the present invention to provide a
digital wireless telephone system, in which the interval in an
intermittent reception operation of a mobile station is increased,
so that a continuous standby period of time of the mobile station
is increased to reduce power consumption of the mobile station.
[0008] According to a first aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0009] In a digital wireless telephone system comprising a mobile
station provided with a reception portion, which portion is timed
in its turning-on-power operation to a paging channel contained in
a sending signal issued from a telephone exchange to the mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, the improvement wherein:
[0010] when an intermittent standby operation is available, the
telephone exchange sends out a paging message in an intermittent
superframe reception group and in a paging channel group, for which
groups the mobile station is waiting; and
[0011] the mobile station receives broadcast information, specifies
an intermittent reception group on the basis of the contents of
intermittent standby information contained in the broadcast
information, and performs its intermittent standby reception
operation in the reception group having been thus specified.
[0012] In the digital wireless telephone system having the above
construction, the mobile station performs the intermittent standby
reception operation based on the intermittent standby information
contained in the broadcast information having been received by the
mobile station, so that the interval in such intermittent reception
operation is increased, whereby the continuous standby period of
time of the mobile station is also increased so as to reduce the
power consumption of the mobile station.
[0013] According to a second aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0014] The digital wireless telephone system as set forth in the
first aspect of the present invention, wherein the telephone
exchange comprises:
[0015] an intermittent reception extension information setting
means for setting the contents of intermittent standby information
in an extension information element contained in the broadcast
information;
[0016] a subscriber's information discriminating means for
discriminating subscriber's information;
[0017] an intermittent reception group analyzing means for
analyzing the intermittent reception group of the mobile station,
on the basis of a discrimination result obtained from the
subscriber's information discriminating means and of the
intermittent standby information having been set by the
intermittent reception extension information setting means; and
[0018] a message sending means for sending out the paging message
in an intermittent reception group and the paging channel group,
for which groups the mobile station is waiting.
[0019] The digital wireless telephone system having the above
construction is preferable in that the mobile station performs the
intermittent standby reception operation based on the intermittent
standby information contained in the broadcast information having
been received by the mobile station to further increase the
interval in such intermittent reception operation.
[0020] According to a third aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0021] The digital wireless telephone system as set forth in the
first aspect of the present invention, wherein
[0022] defined as the contents of intermittent standby information
in the broadcast information are:
[0023] an extension information element length; and
[0024] an intermittent standby information element comprising an
intermittent standby superframe interval and an intermittent
standby superframe counter.
[0025] The digital wireless telephone system having the above
construction is preferable in that the system is capable of
arbitrarily setting the interval in the intermittent standby
operation of the mobile station, and also capable of performing
both synchronization and compensation of such interval.
[0026] According to a fourth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0027] In a digital wireless telephone system comprising a mobile
station provided with a reception portion, which portion is timed
in its turning-on-power operation to a paging channel contained in
a sending signal issued from a telephone exchange to the mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, the improvement wherein:
[0028] the telephone exchange retrieves both of location
information and subscriber's information from a subscriber's
information memory, and sends out a paging message in both an
intermittent superframe reception group and a paging channel group,
for which groups the mobile station is waiting; and
[0029] the mobile station receives broadcast information, specifies
an intermittent reception group on the basis of an intermittent
standby superframe interval having been set in its own unit by
means of an intermittent standby superframe counter, and performs
its intermittent standby reception operation in the reception group
having been thus specified.
[0030] In the digital wireless telephone system having the above
construction, the mobile station uses the intermittent standby
superframe counter contained in the broadcast information,
specifies the intermittent reception group on the basis of the
intermittent standby superframe interval having been set in its own
unit, and performs the intermittent standby reception operation in
the reception group thus specified, which enables the system to
increase the interval in the intermittent reception operation of
the mobile station without providing in its subscriber's
information memory any information indicating whether or not the
mobile station is adapted to perform a high-efficiency operation,
whereby the continuous standby period of time of the mobile station
is increased, and the mobile station has its power consumption
decreased.
[0031] According to a fifth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0032] The digital wireless telephone system as set forth in the
fourth aspect of the present invention, wherein:
[0033] the telephone exchange comprises:
[0034] a Cs information setting means for setting an intermittent
standby superframe counter information element in an extension
information element contained in the broadcast information;
[0035] an intermittent reception group analyzing means for
analyzing the intermittent reception group of the mobile station,
on the basis of the location information and the subscriber's
information both retrieved from a subscriber's information memory;
and
[0036] a message sending means for sending out the paging message
in the intermittent superframe reception group and the paging
channel group, for which groups the mobile station is waiting;
[0037] while the mobile station comprises:
[0038] a Pi memory means for recording the intermittent standby
superframe interval.
[0039] The digital wireless telephone system having the above
construction is preferable in that the mobile station receives the
broadcast information, uses the intermittent standby superframe
counter contained in the broadcast information, and performs the
intermittent standby reception operation at the intermittent
standby superframe intervals of its own unit.
[0040] According to a sixth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0041] In a digital wireless telephone system comprising a mobile
station provided with a reception portion, which portion is timed
in its turning-on-power operation to a paging channel contained in
a sending signal issued from a telephone exchange to the mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, the improvement wherein:
[0042] the telephone exchange retrieves both of location
information and subscriber's information from a subscriber's
information memory, and continuously sends out an inter-superframe
paging message in a paging channel group, for which groups the
mobile station is waiting, the number of the inter-superframe
paging messages being the same value as that of intermittent
standby superframe intervals; and
[0043] the mobile station receives broadcast information, and
performs its intermittent standby reception operation, on the basis
of both the broadcast information and the contents of intermittent
standby information which contains the intermittent standby
superframe interval having been set in its own unit.
[0044] In the digital wireless telephone system having the above
construction, the mobile station is capable of performing, without
involving any delay time, the high-efficiency intermittent
reception operation in the paging messages thus continuously
transmitted, on the basis of both the broadcast information and the
intermittent standby information having been set in its own
unit.
[0045] According to a seventh aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0046] The digital wireless telephone system as set forth in the
sixth aspect of the present invention, wherein:
[0047] the telephone exchange comprises:
[0048] a PCH group analyzing means for analyzing the paging channel
group, for which group the mobile station is waiting, on the basis
of the location information and the subscriber's information both
retrieved from a subscriber's information memory; and
[0049] a message continuously sending out means for continuously
sending out an inter-superframe paging message in a paging channel
group, for which group the mobile station is waiting, the number of
the inter-superframe paging messages being the same value as that
of intermittent standby superframe intervals;
[0050] while the mobile station comprises:
[0051] an intermittent reception information memory means for
recording the contents of intermittent standby information
containing the intermittent standby superframe interval.
[0052] The digital wireless telephone system having the above
construction is preferable in that the mobile station receives the
broadcast information, uses the intermittent standby information
having been set in its own unit, and performs the intermittent
standby reception operation so that the interval in such
intermittent reception operation is further increased.
[0053] According to an eighth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0054] In a digital wireless telephone system comprising a mobile
station provided with a reception portion, which portion is timed
in its turning-on-power operation to a paging channel contained in
a sending signal issued from a telephone exchange to the mobile
station through a base station, and is held in its de-energized
state in the remaining period of time, the improvement wherein:
[0055] the telephone exchange retrieves both of location
information and subscriber's information from a subscriber's
information memory, and continuously sends out an inter-superframe
paging message in a paging channel group, for which groups the
mobile station is waiting, the number of the inter-superframe
paging messages being the same value as that of intermittent
standby superframe intervals; and
[0056] the mobile station receives broadcast information, and
performs its intermittent standby reception operation, on the basis
of the intermittent standby superframe interval contained in the
broadcast information.
[0057] In the digital wireless telephone system having the above
construction, the mobile station uses the intermittent standby
superframe interval contained in the broadcast information, and
performs the intermittent standby operation in the paging messages
having been continuously transmitted, which enables the mobile
station to performs the high-efficiency intermittent reception
operation without involving any delay time.
[0058] According to a ninth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0059] The digital wireless telephone system as set forth in the
eighth aspect of the present invention, wherein:
[0060] the telephone exchange comprises:
[0061] a Pi information setting means for setting the intermittent
standby superframe interval information element in an extension
information element contained in the broadcast information;
[0062] a PCH group analyzing means for analyzing the paging channel
group, for which group the mobile station is waiting, on the basis
of the location information and the subscriber's information both
retrieved from a subscriber's information memory; and
[0063] a message continuously sending out means for continuously
sending out an inter-superframe paging message in a paging channel
group, for which group the mobile station is waiting, the number of
the inter-superframe paging messages being the same value as that
of the intermittent standby superframe intervals.
[0064] The digital wireless telephone system having the above
construction is preferable in that the mobile station receives the
intermittent standby superframe interval contained in the broadcast
information, and performs the intermittent standby reception
operation so that the interval in such intermittent reception
operation is further increased.
[0065] According to a tenth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0066] The digital wireless telephone system as set forth in the
first aspect of the present invention, wherein:
[0067] in intermittent reception state, the mobile station measures
a perch channel in a peripheral zone after completion of reception
of the paging channel in timing, the number of the peripheral zones
to be measured being the same value as that of the intermittent
standby superframe intervals.
[0068] The digital wireless telephone system having the above
construction is preferable in that the perch channel in the
peripheral zones is measured in timed relationship with the
intermittent reception operation.
[0069] According to an eleventh aspect of the present invention,
the above object of the present invention is accomplished by
providing:
[0070] The digital wireless telephone system as set forth in the
first aspect of the present invention, wherein:
[0071] in intermittent reception state, the mobile station measures
a perch channel in a peripheral zone each time a superframe
appears.
[0072] The digital wireless telephone system having the above
construction is preferable in that the perch channel in the
peripheral zones is measured in timed relationship with the
intermittent reception operation.
[0073] According to a twelfth aspect of the present invention, the
above object of the present invention is accomplished by
providing:
[0074] The digital wireless telephone system as set forth in first
aspect of the present invention, wherein,
[0075] the mobile station measures a bit error rate and a level of
reception, and performs its high efficiency intermittent reception
when both of said bit error rate and said level of reception have
reached a prescribed value for a prescribed period of time. Each
mobile station measures the bit error rate (hereinafter called BER)
and the level of reception each time a superframe appears. The
mobile station also has a counter that counts if both of the BER
and the reception level values have reached prescribed values and
lasts until the next superframe appears. Alternatively, the mobile
station comprises two counters, a first counter which advances when
the BER reaches a prescribed value and lasts for one superframe
(i.e. until the next superframe appears), and a second counter
which advances when the level of reception reaches a prescribed
value and also lasts for one superframe.
[0076] According to a thirteenth aspect of the present invention,
the above object of the present invention is accomplished by
providing:
[0077] The digital wireless telephone system as set forth in the
first aspect of the present invention, wherein,
[0078] in high efficiency intermittent reception, the mobile
station measures a bit error rate and a level of reception, and
stops its high efficiency intermittent reception and performs
ordinary intermittent reception when either said bit error rate or
said level of reception fail to reach a prescribed value for a
prescribed period of time.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0079] The foregoing summary, as well as the following detailed
description of preferred embodiments of the invention, will be
better understood when read in conjunction with the appended
drawings. For the purpose of illustrating the invention, there are
shown in the drawings embodiments which are presently preferred. It
should be understood, however, that the invention is not limited to
the precise arrangements and instrumentalities shown.
[0080] In the drawings:
[0081] FIG. 1 is a schematic block diagram of the digital wireless
telephone system of a first embodiment of the present
invention;
[0082] FIG. 2 is a schematic block diagram of the contents of
broadcast information used in the first embodiment of the present
invention shown in FIG. 1;
[0083] FIG. 3 is a schematic block diagram of the information
element of the intermittent standby information used in the first
embodiment of the present invention shown in FIG. 1;
[0084] FIG. 4 is a schematic block diagram illustrating the
operation of the superframe counter of the intermittent standby
information used in the first embodiment of the present invention
shown in FIG. 1;
[0085] FIG. 5 is a flowchart illustrating an operation performed
after the request-to-receive is made to the mobile station in the
first embodiment of the present invention shown in FIG. 1;
[0086] FIG. 6 is a flowchart illustrating an operation performed
after the power source of the mobile station is turned on, in which
operation the mobile station enters its standby mode in the first
embodiment of the present invention shown in FIG. 1;
[0087] FIG. 7 is a flowchart illustrating an operation performed
after completion of telecommunication of the mobile station, in
which operation the mobile station enters in its standby mode in
the first embodiment of the present invention shown in FIG. 1;
[0088] FIG. 8(a) is a timing chart illustrating the conventional
intermittent reception operation of the mobile station in its
standby mode;
[0089] FIG. 8(b) is a timing chart illustrating the intermittent
reception operation of the mobile station in its standby mode in
the first embodiment of the present invention shown in FIG. 1;
[0090] FIGS. 9(a) and 9(b) are timing charts each illustrating the
intermittent standby operation based on measurement of the
peripheral zone when the mobile station performs its
high-efficiency intermittent reception operation in the first
embodiment of the present invention shown in FIG. 1, wherein FIG.
9(a) shows the perch channels measured at two frequencies (i.e., f1
and f2) in the peripheral zone immediately after receipt of
information of the paging channel (i.e., PCH), and FIG. 9(b) shows
the perch channels measured at a first and a second frequency
(i.e., f1 and f2) in a first and a second superframe,
respectively;
[0091] FIG. 10 is a schematic block diagram of the digital wireless
telephone system of a second embodiment of the present
invention;
[0092] FIG. 11 is a schematic block diagram of the digital wireless
telephone system of a third embodiment of the present
invention;
[0093] FIG. 12 is a schematic block diagram of the digital wireless
telephone system of a fourth embodiment of the present
invention;
[0094] FIG. 13 is a diagram illustrating the information element of
the intermittent standby superframe counter in the second
embodiment of the present invention shown in FIG. 10;
[0095] FIG. 14 is a diagram illustrating the information element of
the intermittent standby superframe interval in the fourth
embodiment of the present invention shown in FIG. 10;
[0096] FIG. 15 is a flow diagram illustrating an operation for
starting high efficiency intermittent reception, according to a
fifth embodiment of the present invention; and
[0097] FIG. 16 is a flow diagram illustrating an operation for
stopping high efficiency intermittent reception, according to a
sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0098] Herein below, the present invention will be described in
detail with reference to the accompanying drawings, in which FIGS.
1 to 4 shows a first embodiment of a digital wireless telephone
system 10 of the present invention. More particularly, in the
drawings: FIG. 1 is a schematic block diagram of the digital
wireless telephone system 10 of the first embodiment; FIG. 2 is a
schematic block diagram of the contents of broadcast information
used in the first embodiment; FIG. 3 is a schematic block diagram
of the information element of the intermittent standby information
used in the first embodiment; and, FIG. 4 is a schematic block
diagram illustrating the operation of the superframe counter of the
intermittent standby information used in the first embodiment.
[0099] In FIG. 1 showing the digital wireless telephone system 10
of the present invention: the reference numeral 11 denotes another
network; 12 a telephone exchange; 13 a subscriber's information
memory; 14 a base station; and 15 a mobile station. The telephone
exchange 12 comprises: a mobile communication switching unit 12a
for radio-controlling the base station 14 having a radio zone in
which the mobile station 15 stays, the mobile communication
switching unit 12a also providing a telecommunication service to
the mobile station 15 through the base station 14; a subscriber's
information discrimination means 12b for judging whether or not the
intermittent standby operation of the first embodiment of the
present invention is available, on the basis of information
retrieved from a subscriber's information memory 13; an
intermittent reception extension information setting means 12c for
setting intermittent standby information contained in information
(i.e., BCCH) which should be broadcast to all the mobile stations
15 staying in a cell or radio zone; an intermittent reception group
analyzing means 12d for analyzing an intermittent reception group
of the mobile stations 15 having received such information (i.e.,
BCCH); and, a message sending means 12e for sending paging
information through the mobile communication switching unit
12a.
[0100] The subscriber's information memory 13 is a memory, which
functions as a data base in the network, records both the
subscriber's information and location registration information in
order to provide a service to the mobile station 15, and is
provided with an intermittent standby allowed/not allowed
information memory means 13a for recording availability of a
high-efficiency intermittent standby operation.
[0101] In general, a control signal used in telecommunication
between the network and the mobile station 15 is of a one-way
channel or of a two-way channel. Such control signal is constructed
of: a broadcast channel (i.e., BCCH), which is a one-way channel
for broadcasting the control information to the mobile stations 15
in order to transfer information as to an information channel
structure necessary for location registration and also information
as to the system 10; a paging channel (i.e., PCH), which is a
one-way channel for broadcasting the same information to the mobile
stations 15 in a paging area; and, a separate cell channel (i.e.,
SCCH) for transferring both the information necessary for
connection control and the control information other than the
paging information.
[0102] As shown in FIG. 2, the contents of the broadcast
information message which is broadcast from the network to the
mobile station 15. Such contents comprise a plurality of
information elements, for example such as: message type; network
number; restriction information; control channel structure
information; and, like information elements, each of which has a
predetermined information length in octet.
[0103] In the first embodiment of the present invention shown in
FIG. 1, the intermittent standby information is previously defined
in the extension information element contained in the broadcast
information by the intermittent reception extension information
setting means 12c. In other words, as shown in FIG. 3, in the first
embodiment of the present invention: the information element length
(i.e., K) of the extension information contained in the broadcast
information is defined to be K=1; the intermittent standby
information is defined by one information length, i.e., 1 octet;
the 5th to the 8th bit contained in such 1 octet are used as an
intermittent standby superframe interval (i.e., Pi) for determining
an interval in the intermittent standby operation, while the 1st to
the 4th bit contained in such 1 octet are used as an intermittent
standby superframe counter (i.e., Cs) for counting the number of
the superframes.
[0104] This intermittent standby superframe interval (i.e., Pi)
specifies the superframe interval with which the mobile station 15
performs its intermittent reception operation (hereinafter referred
to as the high-efficiency intermittent reception operation) in the
first embodiment of the present invention. The intermittent standby
superframe interval (i.e., Pi) is set at any one of values 1 to 15
in binary.
[0105] On the other hand, the intermittent standby superframe
counter (i.e., Cs) is set for achieving synchronization and
compensation of the superframe interval when the mobile station 15
performs the high-efficiency intermittent reception operation.
Further, as shown in FIG. 4, a value of this intermittent standby
superframe counter (i.e., Cs value) increases one by one from zero
to a value of (Pi-1) each time the number of the superframes
increases. When the value of this intermittent standby superframe
counter (i.e., Cs value) reaches the value of (Pi-1), a value of a
subsequent intermittent standby superframe counter (i.e., Cs value)
is reset to zero. Incidentally, since the values of the
intermittent standby superframe counter (i.e., Cs) differ in
different superframes as described above, the contents of the
broadcast information differ in different superframes. In this
case, however, any operation for varying the broadcast information,
which instructs the mobile station 15 to receive the broadcast
information so as to ensure that the mobile station 15 receives
such information without fail, is not performed.
[0106] Now, the intermittent reception operation of the first
embodiment of the present invention will be described with
reference to the drawings, in which FIG. 5 is a flowchart
illustrating an operation performed after the request-to-receive is
made to the mobile station 15 in the first embodiment of the
present invention.
[0107] As shown in FIG. 5, in a step ST1, a request-to-receive is
made from another network 11 to the mobile station 15. The step ST1
is followed by a subsequent step ST2, in which the mobile
communication switching unit 12a retrieves location information and
subscriber's information from the subscriber's information memory
13, and concurrently retrieves information (i.e., flag indicating
availability of the intermittent standby operation) from the
intermittent standby allowed/not allowed information memory means
13a, which flag indicates whether or not the high-efficiency
intermittent reception operation of the first embodiment of the
present invention is available.
[0108] Then, the step ST2 is followed by a subsequent step ST3, in
which the availability of the high-efficiency intermittent
reception operation is judged by the subscriber's information
discrimination means 12b on the basis of the information retrieved
from the subscriber's information memory 13.
[0109] In the step ST3, when it is judged that the high-efficiency
intermittent reception operation is available, the step ST3 is
followed by a subsequent step ST4, in which, on the basis of the
intermittent standby information previously set by the intermittent
reception extension information setting means 12c and also based on
the mobile station's number contained in the subscriber's
information and like information, the intermittent reception group
analyzing means 12d analyzes both the intermittent superframe
reception group (i.e., Is) and the paging channel (i.e., PCH) of
the control channel.
[0110] After completion of such analysis, the step ST4 is followed
by a subsequent step ST5, in which: in both the intermittent
superframe reception group (i.e., Is) and the PCH group (i.e., Ip)
of the control channel, the message sending means 12e sends out a
paging message to the mobile station 15 through the mobile
communication switching unit 12a and the base station 14.
[0111] On the other hand, in the step ST3, when the subscriber's
information discrimination means 12b judges, on the basis of the
information retrieved from the subscriber's information memory 13,
that the high-efficiency intermittent reception operation is not
available, the step ST3 goes to a step ST5. In the step ST5, the
base station 14 sends out the paging message to the mobile station
15 which is not capable of performing the high-efficiency
intermittent reception operation. In this case, within a cell, the
control channel is often constructed of a plurality of radio
channels.
[0112] Consequently, the paging channels (i.e., PCH) are grouped
into the PCH group (i.e., Ip) for the intermittent reception
operation of the mobile station 15. As for analysis of the
intermittent superframe reception group (i.e., Is), for example,
when "n" represents in decimal notation a value of the lower 2
octets of the mobile station's number, the intermittent superframe
reception group (i.e., Is) is determined by the following
calculation: namely
Is=n mod Pi
[0113] The above calculation represents the remainder obtained by
dividing the n by the Pi.
[0114] FIG. 6 is a flowchart illustrating an operation performed
after the power source of the mobile station 15 is turned on, in
which operation the mobile station 15 enters its standby mode in
the first embodiment of the present invention.
[0115] In the flowchart shown in FIG. 6, when the power source of
the mobile station 15 is turned on, perch channels stored in a ROM
and like memory means of the mobile station 15 are scanned in a
step ST11, as is in the case of the mobile station 15 not capable
of performing the high-efficiency intermittent reception
operation.
[0116] Then, the step ST11 is followed by a subsequent step ST12,
in which a table of the channels each clearing a casting-out level
is prepared in the order of channels, so that the perch channel is
set. The step ST12 is immediately followed by a subsequent step
ST13, in which a layer 1 operation is performed.
[0117] After that, the step ST13 is followed by a subsequent step
ST14, in which the broadcast information is received. In receiving
the broadcast information, also received are: message type; network
number; restriction information; control channel structure
information; and, like information. In addition to the above,
further received are information elements of the intermittent
standby information, provided that the information element length
of the extension information (i.e., K) is not zero.
[0118] When a plurality of the control channels exist, the same
reception operation as described above is performed in the control
channel in which its own unit 15 should stay. Then, the step ST14
is followed by a subsequent step ST15, in which it is judged
whether or not the intermittent standby information exists.
[0119] When both the information element length of the extension
information (i.e., K) and the information element of the
intermittent standby information exist in the broadcast information
having been received, the step ST15 is followed by a subsequent
step ST16, in which the intermittent reception group of its own
unit 15 is specified on the basis of the value of the intermittent
standby superframe interval (i.e., Pi) contained in the information
element of the intermittent standby information.
[0120] After that, the step ST16 is followed by a subsequent step
ST17, in which the hyperintermittent reception operation is
performed on the basis of the intermittent standby information. In
the step ST15, when the information element of the intermittent
standby information is not contained in the broadcast information
having been received, the step ST15 goes to a step ST18, in which
an ordinary standby operation is performed. In this connection, the
intermittent reception group is specified in the same manner as
that used in determining the intermittent superframe reception
group (i.e., Is) in the above.
[0121] FIG. 7 is a flowchart illustrating an operation performed
after completion of telecommunication of the mobile station 15, in
which operation the mobile station 15 enters its standby mode in
the first embodiment of the present invention.
[0122] As shown in FIG. 7, after completion of telecommunication of
the mobile station 15 in the first embodiment of the present
invention, in a step ST21 the mobile station 15 catches a standby
channel upon disconnection of such telecommunication, on the basis
of the contents of a layer 3 system information message which is
received when the telecommunication is disconnected.
[0123] After that, the step ST21 is followed by a subsequent step
ST22, in which: the broadcast information is received as is in the
flowchart of FIG. 6 starting from the POWER ON; in addition to
reception of the message type, network number, restriction
information, control channel structure information and like
information, the information element of the intermittent standby
information is received when the information element length of the
extension information (i.e., K) is not zero. Further, in case that
a plurality of the control channels exist, the same reception
operation is performed in the control channel in which its own
mobile station 15 should stays.
[0124] Then, the step ST22 is followed by a subsequent step ST23,
in which it is judged whether or not the intermittent standby
information exist. In case that the information element length of
the extension information (i.e., K) is not equal to zero in the
broadcast information having been received, and that the
information element of the intermittent standby information exist
in such broadcast information, the step ST23 is followed by a
subsequent step ST24, in which the intermittent reception group of
its own mobile station 15 is specified on the basis of a value of
the intermittent standby superframe interval (i.e., Pi) contained
in the information element of the intermittent standby
information.
[0125] After that, the step ST24 is followed by a subsequent step
ST25, in which the hyperintermittent reception operation is
performed based on the intermittent standby information. On the
other hand, in the step ST23, when any information element of the
intermittent standby information is not found in the broadcast
information having been received, the step ST23 goes to a step
ST26, in which an ordinary standby operation is performed.
[0126] FIG. 8(b) is a timing chart illustrating the intermittent
reception operation of the mobile station 15 in its standby mode in
the first embodiment of the present invention. Incidentally, in
FIG. 8(b): the reference character BCCH denotes a broadcast
channel; S a separate cell channel (i.e., SCCH); and, P a paging
channel (i.e., PCH).
[0127] As shown in FIG. 8(b), in the high-efficiency intermittent
reception operation which is performed at a time of the POWER ON
shown in FIG. 6 or performed after completion of telecommunication
shown in FIG. 7, for example, when the value of the intermittent
standby superframe interval (i.e., Pi) is 2 and the intermittent
superframe reception group (i.e., Is) is zero, the reception
portion of the mobile station 15 is turned on so as to receive the
paging channel when a value of the intermittent standby superframe
counter (i.e., Cs) is zero; and, after two superframe intervals
(i.e., 720 milliseconds.times.2), the reception portion of the
mobile station 15 is turned on again.
[0128] Incidentally, the mobile station 15 performing the
high-efficiency intermittent reception operation receives
periodically the broadcast information for realizing
synchronization of the intermittent standby superframe counter
(i.e., Cs). At this time, though a timing in such periodical
reception operation is arbitrarily determined, it is possible to
perform such periodical reception operation at intervals of 5
minutes at maximum.
[0129] Further, in order to enable the mobile station 15 to perform
the high-efficiency intermittent reception operation even when in
roaming state, any roaming of the mobile station 15 into other
network provider groups is not included here when availability of
the high-efficiency intermittent reception operation is judged.
[0130] In the digital wireless telephone system 10 of the present
invention having the above construction, when a request-to-receive
is made to the mobile station 15 which is capable of performing the
high-efficiency intermittent reception operation, the telephone
exchange retrieves both the location information and the
subscriber's information from the subscriber's information memory
13, and further concurrently retrieves information from the
intermittent standby allowed/not allowed information memory means
13a.
[0131] Then, the subscriber's information discrimination means 12b
judges availability of the intermittent standby operation. As a
result, when it is judged that the intermittent standby operation
is available, the intermittent reception group analyzing means 12d
specifies the intermittent reception group on the basis of both the
intermittent standby superframe interval (i.e., Pi), which has been
set in the intermittent reception extension information setting
means 12c, and the intermittent standby superframe counter (i.e.,
Cs).
[0132] Then, the paging message is transmitted from the message
sending means 12e to the mobile station 15 through both the mobile
communication switching unit 12a and the base station 14 in the
intermittent superframe reception group (i.e., Is) and the PCH
group (i.e., Ip) of the control channel, which groups (i.e., Is and
Ip) the mobile station 15 is waiting for. After its power source is
turned on, the mobile station 15 performs its ordinary operations
such as: a perch channel scanning operation; a perch channel
setting operation; and, a layer 1 operation.
[0133] After that, the mobile station 15 receives the broadcast
information in its ordinary broadcast information reception
operation. Further, the mobile station 15 performs an additional
reception operation for receiving the information element of the
intermittent standby information when the value of the information
element length of the extension information (i.e., K) is not equal
to zero.
[0134] When the broadcast information having been received contains
the information element of the intermittent standby information,
the intermittent reception group is specified based on the
intermittent standby superframe interval (i.e., Pi). Then, the
mobile station 15 enters its high-efficiency intermittent reception
mode in the thus specified intermittent reception group.
[0135] On the other hand, after completion or disconnection of
telecommunication, the mobile station 15 catches a standby channel
for performing the standby operation after such disconnection, on
the basis of the contents of a layer 3 system information message
obtained at a time of the disconnection.
[0136] After that, the ordinary broadcast information reception
operation is performed as described above. In addition to such
broadcast information reception operation, an additional reception
operation is performed to receive both the information element of
the extension information (i.e., K) and the information element of
the intermittent standby information.
[0137] In this case, when the information element of the
intermittent standby information is contained in the broadcast
information thus received, the intermittent reception group is
specified on the basis of its intermittent standby superframe
interval (i.e., Pi), so that the mobile station 15 enters the
high-efficiency intermittent reception mode in such intermittent
reception group.
[0138] Consequently, in the high-efficiency intermittent reception
operation of the mobile station 15 in the first embodiment of the
present invention, it is possible to perform the intermittent
reception operation at intervals equal to 15 superframe intervals
at maximum as to the intermittent standby superframe interval
(i.e., Pi), on the basis of the intermittent standby information
having been arbitrarily set. Consequently, it is possible to
increase the continuous standby period of time of the mobile
station 15, and, therefore possible to reduce its power consumption
by increasing the interval of the intermittent reception
operation.
[0139] FIGS. 9(a) and 9(b) are timing charts each illustrating the
intermittent standby operation based on measurement of the
peripheral zone when the mobile station 15 performs its
high-efficiency intermittent reception operation in the first
embodiment of the present invention, wherein: FIG. 9(a) shows the
perch channels measured at two frequencies (i.e., f1 and f2) in the
peripheral zone immediately after receipt of information of the
paging channel (i.e., PCH); and, FIG. 9(b) shows the perch channels
measured at a first and a second frequency (i.e., f1 and f2,
respectively) in a first and a second superframe, respectively.
Incidentally, in FIGS. 9(a) and 9(b), the reference characters
BCCH, S and P are the same as those described with reference to
FIGS. 8(a) and 8(b).
[0140] Now, a method for measuring a first peripheral zone will be
described.
[0141] In this method, after the mobile station 15 receives the
information of the paging channel (i.e., PCH) when in its
high-efficiency intermittent reception mode, the perch channels of
the peripheral zone are measured, provided that the number of the
perch channels to be measured is the same value as that of the
intermittent standby superframe interval (i.e., Pi).
[0142] For example, in case that the Pi is equal to 2 (i.e., Pi=2),
as shown in FIG. 9(a), two frequencies (i.e., f1 and f2) of the
perch channels in the peripheral zone are measured immediately
after reception of the information of the paging channel (i.e.,
PCH). Further, in case that the Pi is equal to 3 (i.e., Pi=3),
three frequencies (i.e., f1, f2 and f3) of the perch channels in
the peripheral zone are measured immediately after reception of the
information of the paging channel (i.e., PCH).
[0143] Then, a method for measuring a second peripheral zone will
be described. In this method, when the mobile station 15 is in the
high-efficient intermittent reception mode, the perch channels in
the peripheral zone are measured in each one of the superframes
irrespective of any value of the intermittent standby superframe
interval (i.e., Pi). For example, when the Pi is equal to 2 (i.e.,
Pi=2), as shown in FIG. 9(b), one frequency (i.e., f1) of the perch
channel is measured in the first superframe, and then another
frequency (i.e., f2) is measured in the subsequent second
superframe.
[0144] As for measurement of the peripheral zones, the mobile
station 15 is capable of carrying out any one of the above methods
for measuring the first and the second zones.
[0145] Incidentally, the above embodiment of the present invention
has been described in a manner such that: the subscriber's
information memory 13 is provided with the intermittent standby
allowed/not allowed information memory means 13a; the flag
indicating availability of the intermittent standby operation is
stored in the intermittent standby allowed/not allowed information
memory means 13a; and, the subscriber's information discrimination
means 12b judges whether or not the intermittent standby operation
of the mobile station 15 is available.
[0146] In the above embodiment of the present invention, however,
it is also possible to eliminate both the intermittent standby
allowed/not allowed information memory means 13a and the
subscriber's information discrimination means 12b since the network
is capable of calling up the mobile station 15 at any time slot,
provided that the network can find out the time slot which the
mobile station 15 is waiting for.
[0147] Further, in the above embodiment of the present invention,
though: a length of the information element of the extension
information (i.e., K) is defined to be equal to 1 (i.e., K=1); and,
the information elements of the intermittent standby information
are defined in a manner such that a value of the intermittent
standby superframe interval (i.e., Pi) is defined to be 4 bits and
a value of the intermittent standby superframe counter (i.e., Cs)
is defined to be 4 bits, all the above information elements are not
necessarily defined as described above. In other words, they may be
arbitrarily defined, if necessary.
[0148] FIG. 10 is a schematic block diagram of the digital wireless
telephone system 20 of a second embodiment of the present
invention, and FIG. 13 is a diagram illustrating the information
element of the intermittent standby superframe counter in the
second embodiment of the present invention. Incidentally, in FIGS.
10 and 13, the parts which are the same as ones in FIG. 1 have been
given the same reference numerals/characters and are not further
explained.
[0149] In the digital wireless telephone system 20 of the present
invention shown in FIG. 10, a telephone exchange 22 comprises: a
mobile communication switching unit 22a for radio-controlling the
base station 14 having a radio zone in which a mobile station 25
stays, the mobile communication switching unit 22a also providing a
telecommunication service to the mobile station 25 through the base
station 14; a Cs information setting means 22c for setting the
intermittent standby superframe counter information contained in
the broadcast information (i.e., BCCH information) which should be
broadcast to all the mobile station 25 staying in the cell; an
intermittent reception group analyzing means 22d for analyzing an
intermittent reception group of the mobile stations 25 having
received such information (i.e., BCCH); and, a message sending
means 22e for sending paging information through the mobile
communication switching unit 22a.
[0150] The mobile station 25 of the second embodiment of the
present invention is provided with a Pi memory means 25a for
storing an intermittent standby superframe interval having been
previously set. In this second embodiment of the present invention,
the intermittent standby superframe counter is previously set in
the information element of the extension information by means of
the Cs setting means 22c, which extension information is contained
in the broadcast information.
[0151] In other words, as shown in FIG. 13, in the second
embodiment of the present invention: a length of the information
element of the extension information (i.e., K) contained in the
broadcast information is defined to be equal to 1 (i.e., K=1); and,
a length of the information element of the intermittent standby
superframe counter (i.e., Cs) is defined to be equal to 1 octet.
Such value of the intermittent standby superframe counter (i.e.,
Cs) increases from zero to Pi-1 as is in the case of the first
embodiment of the present invention. When the value of the
intermittent standby superframe counter (i.e., Cs) reaches the
Pi-1, a subsequent value of the counter (i.e., Cs) becomes zero. In
construction, the remaining parts of the second embodiment of the
present invention are the same as those of the first embodiment of
the present invention.
[0152] In the digital wireless telephone system 20 of the present
invention having the above construction, when a request-to-receive
is made to the mobile station 25: the telephone exchange 22
retrieves both the location information and the subscriber's
information from the subscriber's information memory 13; the
intermittent reception group analyzing means 22d analyzes both the
intermittent superframe reception group (i.e., Is) and the PCH
group; and, the message sending means 22e sends a message to the
mobile station 25 through both the mobile communication switching
unit 22a and the base station 14. After its power source is turned
on, the mobile station 25 performs its ordinary operations such as:
a perch channel scanning operation; a perch channel setting
operation; and, a layer 1 operation.
[0153] After that, the mobile station 25 receives the broadcast
information in its ordinary broadcast information reception
operation. Further, the mobile station 25 performs an additional
reception operation for receiving both the information element
length of the extension information (i.e., K) and the information
element of the intermittent standby superframe counter.
[0154] In case that: the broadcast information having been received
does not contain any of the information element length of the
extension information (i.e., K) and the information element of the
intermittent standby superframe counter; and, the high-efficiency
intermittent reception operation is not available, the mobile
station 25 performs an ordinary standby reception operation.
[0155] When the broadcast information having been received contains
both the information element length of the extension information
(i.e., K) and the information element of the intermittent standby
superframe counter, the intermittent reception group of its own
mobile station 25 is specified based on the value of the
intermittent standby superframe interval having been stored in the
Pi memory means 25a of the mobile station 25.
[0156] Then, the mobile station 15 enters the high-efficiency
intermittent reception mode in the thus specified intermittent
reception group. On the other hand, after completion or
disconnection of telecommunication, the mobile station 25 catches a
standby channel, which the mobile station 25 is waiting for after
the above disconnection, on the basis of the contents of a layer 3
system information message obtained at a time of the disconnection
of telecommunication.
[0157] After that, the ordinary broadcast information reception
operation is performed as described above. In addition to such
broadcast information reception operation, an additional reception
operation is performed to receive both the information element
length of the extension information (i.e., K) and the information
element of the intermittent standby superframe counter.
[0158] In this case, when both the information element length of
the extension information (i.e., K) and the information element of
the intermittent standby superframe counter are contained in the
broadcast information thus received, the intermittent reception
group is specified on the basis of the intermittent superframe
interval (i.e., Pi), so that the mobile station 25 enters the
high-efficiency intermittent reception mode in such intermittent
reception group.
[0159] Consequently, as is in the first embodiment of the present
invention, the high-efficiency intermittent reception operation of
the mobile station 25 is available also in the second embodiment of
the present invention. As a result, it is possible to increase the
continuous standby period of time of the mobile station 25, and,
therefore possible to reduce the power consumption of the mobile
station 25.
[0160] In this second embodiment of the present invention, the
subscriber's information memory 13 is not required to have
information as to availability of the high-efficiency intermittent
standby operation of each of the subscribers. Incidentally, the
same method for measuring the peripheral zone as that of the first
embodiment of the present invention is also used in the second
embodiment of the present invention in a condition in which the
mobile station 25 is in the high-efficiency intermittent standby
mode. More particularly, the above method for measuring the
peripheral zone may be either the method for measuring the first
peripheral zone or the method for measuring the second peripheral
zone.
[0161] FIG. 11 is a schematic block diagram of the digital wireless
telephone system of a third embodiment of the present invention.
Incidentally, in FIG. 11, the parts, which are the same as ones in
FIG. 1 showing the first embodiment of the present invention, have
been given the same reference numerals/characters and are not
further explained.
[0162] In the digital wireless telephone system 30 of the present
invention shown in FIG. 11, a telephone exchange 32 comprises: a
mobile communication switching unit 32a for radio-controlling the
base station 14 having a radio zone in which a mobile station 35
stays, the mobile communication switching unit 32a also providing a
telecommunication service to the mobile station 35 through the base
station 14; a PCH group analyzing means 32d for analyzing the
paging channel group; and, a message continuously-sending means 32e
for continuously sending the paging message through the mobile
communication switching unit 32a for a period of time equal to a
plurality of superframes, the number of which is the same as that
of the Pi's.
[0163] Further, the mobile station 35 of the third embodiment of
the present invention is provided with an intermittent reception
information memory means 35a, which stores intermittent reception
information such as an intermittent standby superframe interval and
like information having been previously set. In construction, the
remaining parts of the third embodiment of the present invention
are the same as those of the first embodiment of the present
invention.
[0164] In the digital wireless telephone system 30 of the present
invention having the above construction, when a request-to-receive
is made to the mobile station 35, the telephone exchange 32
specifies, as is in the case of an ordinary telephone call, a radio
zone in which the mobile station 35 thus called stays. After
completion of specifying the radio zone, the PCH group is analyzed
by the PCH group analyzing means 32d. The message
continuously-sending means 32e continuously sends the paging
message to the mobile station 35 through both the mobile
communication switching unit 32a and the base station 14 for a
period of time equal to a plurality of superframes, the number of
which is the same as that of the Pi's.
[0165] After its power source is turned on, the mobile station 35
performs its ordinary operations such as: a perch channel scanning
operation; a perch channel setting operation; and, a layer 1
operation. After that, the mobile station 35 receives the broadcast
information in its ordinary broadcast information reception
operation.
[0166] Further, the mobile station 35 compares the network number
and the like with the high-efficiency intermittent reception
information having been stored in the intermittent reception
information memory means 35a.
[0167] When the high-efficiency intermittent reception operation is
available, the mobile station 35 initiates the high-efficiency
intermittent reception operation.
[0168] On the other hand, after completion or disconnection of
telecommunication, the mobile station 35 catches a standby channel,
which the mobile station 35 is waiting for after the above
disconnection, on the basis of the contents of a layer 3 system
information message obtained at a time of the disconnection of
telecommunication.
[0169] After that, when the high-efficiency intermittent reception
operation is available, the mobile station 35 initiates the
high-efficiency intermittent reception operation. On the other
hand, when the high-efficiency intermittent reception operation is
not available, the mobile station 35 performs an ordinary standby
reception operation.
[0170] Consequently, as is in the first embodiment of the present
invention, the high-efficiency intermittent reception operation of
the mobile station 35 is available also in the third embodiment of
the present invention.
[0171] As a result, it is possible to increase the continuous
standby period of time of the mobile station 35, and, therefore
possible to reduce the power consumption of the mobile station
35.
[0172] In this third embodiment of the present invention, it is
possible for the mobile station 35 to perform the high-efficiency
intermittent reception operation without involving any time delay
for a telephone call when the telephone exchange 32 continuously
sends the paging message for a period of time equal to a plurality
of the superframes, the number of which is the same as that of the
Pi's.
[0173] Further, in the side of the network, there is no need for
specifying the intermittent superframe reception group (i.e., Is).
Incidentally, the same method for measuring the peripheral zone as
that of the first or the second embodiment of the present invention
is also used in the third embodiment of the present invention in a
condition in which the mobile station 35 is in the high-efficiency
intermittent reception mode. More particularly, the above method
for measuring the peripheral zone may be either the method for
measuring the first peripheral zone or the method for measuring the
second peripheral zone.
[0174] FIG. 12 is a schematic block diagram of the digital wireless
telephone system 40 of a fourth embodiment of the present
invention, and FIG. 14 is a diagram illustrating the information
element of the intermittent standby superframe interval in the
fourth embodiment of the present invention. Incidentally, in FIG.
12, the parts which are the same as ones in FIG. 1 have been given
the same reference numerals/characters and are not further
explained.
[0175] In the digital wireless telephone system 40 of the present
invention shown in FIG. 12, a telephone exchange 42 comprises: a
mobile communication switching unit 42a for radio-controlling the
base station 14 having a radio zone in which a mobile station 45
stays, the mobile communication switching unit 42a also providing a
telecommunication service to the mobile station 45 through the base
station 14; a Pi information setting means 42c for setting the
intermittent standby superframe interval information contained in
information (i.e., BCCH information) which should be broadcast to
all the mobile station 45 staying in the cell; a PCH group
analyzing means 42d for analyzing the paging channel group; and, a
message continuously-sending means 42e for continuously sending the
paging message through the mobile communication switching unit 42a
for a period of time equal to a plurality of superframes, the
number of which is the same as that of the Pi's.
[0176] Further, in this fourth embodiment of the present invention,
the intermittent standby superframe interval is previously set by
means of the Pi setting means 42c in the information element of the
extension information contained in the broadcast information.
[0177] In other words, as shown in FIG. 14, in the fourth
embodiment of the present invention: a length of the information
element of the extension information (i.e., K) contained in the
broadcast information is defined to be equal to 1 (i.e., K=1); and,
a length of the information element of the intermittent standby
superframe interval (i.e., Pi) is defined to be equal to 1 octet.
In construction, the remaining parts of the fourth embodiment of
the present invention are the same as those of the first embodiment
of the present invention.
[0178] In the digital wireless telephone system 40 of the present
invention having the above construction, when a request-to-receive
is made to the mobile station 45: the telephone exchange 42
specifies a radio zone in which the mobile station 45 thus called
stays.
[0179] After completion of specifying the radio zone, the PCH group
is analyzed by the PCH group analyzing means 42d. The message
continuously-sending means 42e continuously sends the paging
message to the mobile station 45 through both the mobile
communication switching unit 42a and the base station 14 for a
period of time equal to a plurality of superframes, the number of
which is the same as that of the Pi's.
[0180] After its power source is turned on, the mobile station 45
performs its ordinary operations such as: a perch channel scanning
operation; a perch channel setting operation; and, a layer 1
operation. After that, the ordinary broadcast information reception
operation is performed. In addition to such broadcast information
reception operation, an additional reception operation is performed
to receive both the information element length of the extension
information (i.e., K) and the information element of the
intermittent standby superframe interval.
[0181] In this case, when both the information element length of
the extension information (i.e., K) and the information element of
the intermittent standby superframe interval are contained in the
broadcast information thus received, the mobile station 45 performs
its high-efficiency intermittent reception operation on the basis
of a value of the Pi in the information element of the intermittent
standby superframe interval. At this time, the network continuously
sends out the paging signal for a period of time equal to a
plurality of the superframes, the number of which is the same as
that of the Pi's.
[0182] Consequently, in the mobile station 45 there is no need for
synchronization of such superframes. On the other hand, after
completion or disconnection of telecommunication, the mobile
station 45 catches a standby channel, which the mobile station 35
is waiting for after the above disconnection, on the basis of the
contents of a layer 3 system information message obtained at a time
of the disconnection.
[0183] After that, the ordinary broadcast information reception
operation is performed. In addition to such broadcast information
reception operation, an additional reception operation is performed
to receive both the information element length of the extension
information (i.e., K) and the information element of the
intermittent standby superframe interval.
[0184] When both the information element length of the extension
information (i.e., K) and the information element of the
intermittent standby superframe interval are contained in the
broadcast information thus received, the mobile station 45 performs
its high-efficiency intermittent standby reception operation on the
basis of the value of the Pi. At this time, as is in the above, the
network is not required to synchronize all the superframes.
[0185] Incidentally, when the high-efficiency intermittent
reception operation is not available, the mobile station 45
performs an ordinary standby reception operation. Consequently, as
is in the first embodiment of the present invention, the mobile
station 45 is capable of performing the high-efficiency
intermittent reception operation in the fourth embodiment of the
present invention. As a result, it is possible to increase the
continuous standby period of time of the mobile station 45, which
reduces the power consumption of the mobile station 45.
[0186] In this fourth embodiment of the present invention, the
telephone exchange 42 continuously sends out the paging message for
a period of time equal to a plurality of the superframes, the
number of which is the same as that of the Pi's. Consequently, it
is possible for the mobile station 45 to perform the
high-efficiency intermittent reception operation without involving
any time delay for a telephone call.
[0187] Further, inside the network, there is no need for specifying
the intermittent superframe reception group (i.e., Is).
Incidentally, the same method for measuring the peripheral zone as
that of the first or the second embodiment of the present invention
is also used in the fourth embodiment of the present invention in a
condition in which the mobile station 45 is in the high-efficiency
intermittent reception mode. More particularly, the above method
for measuring the peripheral zone may be either the method for
measuring the first peripheral zone or the method for measuring the
second peripheral zone.
[0188] In a fifth embodiment, high-efficiency intermittent
reception is initiated on condition that prescribed values of bit
error rate (BER), of reception level or of both the BER and the
reception level are satisfied for a prescribed period of time, in
order that the mobile station perform high efficiency intermittent
reception under more stable conditions.
[0189] The mobile station measures the BER and the reception level,
and advances a counter (not shown)if both the values of the BER and
the reception level reach prescribed values and if both the BER and
the reception level exceed the prescribed values until the next
superframe appears. The mobile station meets the criteria for
starting high-efficiency intermittent reception if the value of the
counter is greater than a prescribed value.
[0190] By our experiment, as for the reception level, the most
preferred condition is that the reception level be greater than 16
dB. and last for a period of 9 or more superframes. With regard to
the BER, the most preferred condition is that the BER be under 0.3%
and last for a period of 9 or more superframes.
[0191] FIG. 15 is a flowchart illustrating an operation performed
while the mobile station is in ordinary intermittent reception
before high-efficiency intermittent reception is initiated (ST51).
As shown in FIG. 5, FIG. 6, and FIG. 7, the mobile station
recognizes the intermittent standby information, and prepares to
perform high-efficiency intermittent reception (ST52). The mobile
station analyzes the BER and the reception level, and the counter
in the mobile station counts the period for which the BER and the
reception level exceed prescribed values. The counter advances
whenever both of the prescribed values are satisfied. If the count
of the counter is greater than a prescribed value (ST53), the
mobile station specifies an intermittent reception group (ST54),
and performs high-efficiency intermittent reception (ST55). If the
counter is not over the prescribed value, the mobile station keeps
performing ordinary reception (ST56).
[0192] As a result of above process, the mobile station performs
more stable high-efficiency intermittent reception than the
preceding embodiments.
[0193] In a sixth embodiment, the high-efficiency intermittent
reception is stopped and the mobile station performs ordinary
intermittent reception on a condition that the prescribed values of
BER, of reception level or of both of them are unsatisfied in order
that mobile station could perform high-efficiency intermittent
reception under more stabilized conditions.
[0194] The mobile station recognizes whether intermittent standby
information exists or not, as in the other embodiments. If it does
not exist, it stops the high- efficiency intermittent reception and
performs ordinary intermittent reception.
[0195] The mobile station measures the BER, the reception level,
and advances a counter (not shown) if either the BER or the
reception level fails to reach a prescribed value which lasts until
the next superframe appears. If the value of counter is over a
prescribed value it means that the mobile station has an
inappropriate BER or reception level and the high-efficiency
intermittent reception should be stopped, and the ordinary
intermittent reception should be performed.
[0196] By our experiment, as for the reception level, the most
preferred condition for stopping high-efficiency intermittent
operation is when the reception level is under 10 dB, and it lasts
for a period of 9 or more superframes. With regard to the BER, the
most preferred condition is that the BER is over 0.3% and it lasts
for a period of 9 or more superframes.
[0197] FIG. 16 is a flowchart illustrating an operation performed
while the mobile station is performing high-efficiency intermittent
operation (ST61). In this case the mobile station keeps measuring
the BER, and the reception level. At step ST62, the mobile station
recognizes whether the intermittent standby information exists or
not (ST62) and stops the high-efficiency reception and performs
ordinary intermittent reception if the intermittent standby
information does not exist (ST66).
[0198] The counter advances on condition that either the BER or
reception level is less than a prescribed value. If the value of
the counter is over the prescribed value (ST63), the mobile station
stops high efficiency intermittent reception, and performs ordinary
intermittent reception (ST66). If the counter is not over the
prescribed value, the mobile station keeps performing
high-efficiency intermittent reception (ST65). As a result of above
process, the mobile station performs more stable high-efficiency
intermittent reception than the preceding embodiments.
[0199] As described above, in the present invention having the
above construction, the mobile station performs the high-efficiency
intermittent reception operation, which increases the interval in
the intermittent reception operation, and, therefore increases the
continuous standby period of time of the mobile station, so that
the power consumption of the mobile station is reduced.
[0200] It will be appreciated by those skilled in the art that
changes could be made to the embodiments described above without
departing from the broad inventive concept thereof. It is
understood, therefore, that this invention is not limited to the
particular embodiments disclosed, but it is intended to cover
modifications within the spirit and scope of the present invention
as defined by the appended claims.
* * * * *